Centering-tool.



J. A; PETTA.

OENTERING TOOL.

APPLICATION FILED MAR. 27, 1908 908,324. Patented Dec. 29, 1908.

Ewyentoz Q/Vi :41 zoom THE uonms PETERS ca., WASHINGYUN, n. c.

UNITED STATES JOHN A. PETTA, OF SEATTLE, WASHINGTON.

CENTERING-TOOL.

Specification of Letters Patent.

Patented Dec. 29, 1908.

Application filed March 27, 1908. Serial No. 423,736.

T 0 all whom it may concern:

Be it known that I, JOHN A. PETTA, a citizen of the United States, residing at Seattle, in the county of King and State of \Vashington, have invented new and useful Improvements in Centering-Tools, of which the following is a specification.

This invention relates to a jewelry tool and is designed especially for use in obtaining centers while parts are mounted in the chuck of a lathe, as for instance, in finding j ting of the insertion of a suitable instrument 1 for forcing the drill loose when it is desired to remove the same. Disposed inwardly from I the slot 6 is a recess 7 for receiving the inner end of a screw 8 that constitutes the stop for E limiting the movement of the sleeve 9 that 1 houses the drill. The outer end of the sleeve is contracted as shown at 10 and between the l opposite or inner end of the sleeve and inner j Wall of the socket 2 is a helical spring 11 that j encircles the shank 3, the spring being under the center of a staff in order to bore the such tension as to normally hold the sleeve same to replace a broken pivot. The invention has for one of provide a centering tool of this character which is comparatively simple and inexpenj sive to manufacture and convenient and reliable in use.

A further object of the invention is the provision of a tool consisting of the shank in which the drill is mounted and on which is a slidable sleeve that is held projected beyond the oint of the drill by a spring, the outer end 0 the sleeve serving to receive the end of the stafi or other part of a watch or the like to be centered.

With these objects in view and others as will appear as the description proceeds, the invention comprises the various novel features of construction parts which will be more fully described hereinafter and set forth with particularity absolute center in the claims appended hereto.

In the accompanying drawing which illustrates one of the embodiments of the invention:--Figure 1 is a central longitudinal sectional view of the tool showing the sleeve in to those skil j central position the pressure is applied to and arrangement of l applied by projected so that the outer end of the latter its objects to will extend beyond, the point of the drill,

1 thus protecting the latter from injury when the tool is not in use. vided with a chamber 12 normally closed by a cap such as a screw 13 so that drills of different sizes may be stored.

In practice the Work to be centered is mounted in a chuck of a lathe and as the work rotates the tool is applied thereto by placing the outer end of the sleeve in engagement with the work and while thus held 1iln t e The handle in a direction toward the work.

j sleeve 9 is thus pressed inwardly so as to jbring the drill into engagement with the work, the spring 11 yielding-to the pressure the operator on the handle. In this manner, the work can be drilled and an obtained.

From the foregoing description taken in connection with the accompanying drawing,

1 the advantages of the construction and of the method of operation will be readily apparent ed in the art to which the invennormal position. Fig. 2 is a similar view tion appertains and while I have described showing the sleeve pressed inwardly as the process of drilling.

in the principles of operation of the invention,

together with the device which I now con- Similar reference characters are employed sider to be the best embodiment thereof, I

to designate corresponding parts throughout the several views.

Referring to the drawing, A designates the handle of any approved material and design and having at its inner end two alining sockets 1 and 2 of different diameters, the socket of smaller diameter being innermost. Fitted in the socket 2 is a fixed rod 3 forming the shank of the tool, the rod being of such length as to project a suitable distance out or the socket 1. The outer end of the shank or rod 3 has a central bore 4 for receiving the drill 5 and adjacent the extremity of the shank is a transverse slot 6 into which the rear end of the tool extends, the slot permit desire to have it understood that the device shown is merely illustrative and that such what The handle A is prohoused Within the larger socket and bearing at one end on the inner Wall of the latter and at its opposite end on the inner extremity-of the sleeve and encircling the said rod,,.said 5 rod having a slot, and a stop removably 'carried by the slot, and engaging in the slotfo'r' limiting the movement of the sleeve and forming the sole means for retaining the latter on the rod, said sleeve having its outer end normally projecting beyond the drill in the rod.

2. The combination of a handle having a socket in its end, a rod secured in the socket and having its end provided with a central 15 bore andrecesses, a drill arranged in the said rod, acounter-sunk'screw borev'vith its inner end extending into one of the recesses, a sleeve slidably mounted on the on the sleeve and extending into the other recess of the'rod, and a'spring arranged to normally hold the sleeve with its outer end projecting beyond the point of the drill and permitting the sleeveto yield inwardly into the socket.

In testimony whereof I affix my signature in presence of tWo Witnesess.

JOHN A. PETTA.

Witnesses:

SAML. H. JOHNSTON, JoEL P. GEER. 

